FKIE_CVE-2026-74524

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Fix out-of-bounds page-table walk during memory hot-remove remove_pud_mapping() and remove_p4d_mapping() obtain a child table base with pud_offset(p4dp, 0) and p4d_offset(pgd, 0), then add the index for addr. RISC-V folds page-table levels at runtime. When a level is folded, its offset helper returns the parent entry itself, but the index can still be nonzero. Adding it walks past the parent table. Sv48 folds P4D, while Sv39 folds both P4D and PUD, so memory hot-remove can descend into unrelated memory and pass an invalid page to __free_pages(). This can trigger: kernel BUG at include/linux/mm.h:1810! VM_BUG_ON_PAGE(page_ref_count(page) == 0) arch_remove_memory+0x1e/0x5c try_remove_memory+0x15e/0x200 remove_memory+0x24/0x3c Only add the index when the corresponding page-table level is enabled, matching p4d_offset() and pud_offset().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1bb0ef8069ef158d245bac91ac178bb4f1a7ccd2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1da6d832eda02d908df11a30ba6a856b98a3dd76
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/54e07a158f7aea2754849d3a5a4cba1ac338ae7e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a0188cc133696627857d16054e43f9ebc7efc821
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/mm/init.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1da6d832eda02d908df11a30ba6a856b98a3dd76",
              "status": "affected",
              "version": "c75a74f4ba19c904c0ae1e011ae2568449409ae4",
              "versionType": "git"
            },
            {
              "lessThan": "54e07a158f7aea2754849d3a5a4cba1ac338ae7e",
              "status": "affected",
              "version": "c75a74f4ba19c904c0ae1e011ae2568449409ae4",
              "versionType": "git"
            },
            {
              "lessThan": "1bb0ef8069ef158d245bac91ac178bb4f1a7ccd2",
              "status": "affected",
              "version": "c75a74f4ba19c904c0ae1e011ae2568449409ae4",
              "versionType": "git"
            },
            {
              "lessThan": "a0188cc133696627857d16054e43f9ebc7efc821",
              "status": "affected",
              "version": "c75a74f4ba19c904c0ae1e011ae2568449409ae4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/riscv/mm/init.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
            {
              "lessThan": "6.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: mm: Fix out-of-bounds page-table walk during memory hot-remove\n\nremove_pud_mapping() and remove_p4d_mapping() obtain a child table base\nwith pud_offset(p4dp, 0) and p4d_offset(pgd, 0), then add the index for\naddr.\n\nRISC-V folds page-table levels at runtime. When a level is folded, its\noffset helper returns the parent entry itself, but the index can still be\nnonzero. Adding it walks past the parent table. Sv48 folds P4D, while Sv39\nfolds both P4D and PUD, so memory hot-remove can descend into unrelated\nmemory and pass an invalid page to __free_pages(). This can trigger:\n\n  kernel BUG at include/linux/mm.h:1810!\n  VM_BUG_ON_PAGE(page_ref_count(page) == 0)\n  arch_remove_memory+0x1e/0x5c\n  try_remove_memory+0x15e/0x200\n  remove_memory+0x24/0x3c\n\nOnly add the index when the corresponding page-table level is enabled,\nmatching p4d_offset() and pud_offset()."
    }
  ],
  "id": "CVE-2026-74524",
  "lastModified": "2026-08-17T06:19:49.290",
  "metrics": {},
  "published": "2026-08-15T13:17:57.660",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1bb0ef8069ef158d245bac91ac178bb4f1a7ccd2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1da6d832eda02d908df11a30ba6a856b98a3dd76"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/54e07a158f7aea2754849d3a5a4cba1ac338ae7e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a0188cc133696627857d16054e43f9ebc7efc821"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.